In summary, a docking process of a large vessel can be tedious and time consuming. The operating costs of a ship or other large vessel can be as high as hundreds of dollars per minute. In addition to operating costs, the docking procedure generally requires an additional person standing on the dock to aid the captain (or other person overseeing operation of the vessel) in guiding the ship to a desired alignment with the dock. Cruise ships, for example, dock at a plurality of ports during each cruise. Excess minutes during each docking can add up to sizeable costs during each cruise. When docking large vessels, the process requires that the vessel be positioned longitudinally along the dock to properly position the ships bitts or other mooring equipment at a desired relation with the docks bitts, cleats, or other mooring equipment.
In more detail, many vessels call on the same port on a regular basis and berth at the same dock or wharf each time they arrive in the port.
In many instances for ships using the same dock on a regular basis, the final docking positioning of a vessel is critical and is virtually the same every time (within inches) in order for the ramps, chiksans (mechanical loading arms for oil tankers), gangway, side ports, cranes to be properly positioned for cargo operations or the skyway for the loading/unloading of passengers.
Currently, a vessel is spotted (positioned) by a harbormaster standing on the dock or a crewmember aboard the vessel to ensure the position of the chiksans, ramps, gangway(s) are correct. This is accomplished by the harbormaster walking up and down the dock or the crewmember walking the deck of the ship checking to ensure the line up of the ship's gangway, ramp, etc. are in proper position. This repetitive process, which is time consuming, is required to be done each time the ship berths even though the vessel is docking at the same berth over and over again and must be berthed within several inches of the predetermined position each time.
Currently, there is no accurate method to visually determine on the bridge of the ship if the vessel is in the proper fore and aft position for cargo operations, chiksans for tankers and/or the skyway used for embarking/disembarking passengers.
When a large vessel is docking and in position, it can be visually challenging on the bridge of the ship which can be 16 stories (approximately 170′) above water to determine minimal fore and aft movement of the vessel when the lines are being put on the dock to secure the vessel. Many times during the docking evolution while lines are being put out, a vessel creeps either fore or aft and must be repositioned due to the virtually unnoticeable fore and aft motion from the bridge several stories high.
The current method of determining the fore and aft movement of a ship is done by eye by horizontally aligning two fixed objects on land to determine fore and aft motion or by using a Doppler speed log and looking at a computer screen to determine the numerical fore and aft motion.
The problem with aligning two fixed objects on land to determine fore/aft movement is that the person's head must remain stationary and eyes fixed on the two objects to determine fore/aft motion accurately. Once the eyes or head move the original reference point is lost.
Doppler is very accurate, however it requires taking your eyes off the side of the vessel and looking at a computer screen. When docking a vessel, the prudent person in charge of maneuvering the vessel is looking down the side of the vessel to monitor the lateral motion, fore/aft motion and the ships lines going out as well to ensure they do not get too taught by the fore/aft motion and part.
During the docking of a vessel, the fore and aft motion of the vessel is currently determined visually by aligning fixed objects on land perpendicular to the vessel. The other alternative is using a Doppler docking system, which is an electronic device that gives the longitudinal and lateral speed of the vessel toward or away from the dock and alongside the dock. The information displayed on the Doppler docking system is displayed on a computer screen and does not provide any visual reference.
At the present time, there is no visual aid available to help determine the fore and aft motion of a vessel alongside the dock or wharf and/or the correct docking position of a vessel which berths at the same dock on a regular basis.
Accordingly, there remains a need in the art for a docking guidance system that enables the ship's controlling officer the ability to quickly, easily, and adequately position a vessel in a precise aligned location respective to a length of a dock.